Negative electrode top cover assembly and secondary battery

Abstract

The application discloses a negative electrode top cover assembly and a secondary battery, which comprises a first insulating piece, a top cover sheet, a second insulating piece, an aluminum piece, a sealing piece, a copper rivet piece and a copper plate, and the top cover sheet is provided with a pole mounting hole; one end of the copper rivet piece is provided with a lug structure, and the other end of the copper rivet piece is riveted with the copper plate; the end face of the lug structure is brazed with the aluminum piece, the sealing piece is sleeved on the copper rivet piece, one end of the sealing piece abuts against the lug structure through the second insulating piece, and the other end of the sealing piece abuts against the copper plate; and the radial dimension of the lug structure is greater than the radial dimension of the pole mounting hole. The negative electrode top cover assembly and the secondary battery provided by the application have the sealing piece arranged between the second insulating piece and the copper plate, so that one end of the sealing piece can abut against and support the lug structure through the second insulating piece, abnormal stress of the copper-aluminum interface is avoided, the structural stability of the negative electrode top cover assembly is improved, and the reliability of the battery is improved.

Description

Technical Field

[0001] This application belongs to the field of secondary battery technology, and particularly relates to negative electrode top cover assembly and secondary battery. Background Technology

[0002] Existing blade battery cells typically consist of a positive electrode top cover assembly, a negative electrode top cover assembly, and a casing. In traditional negative electrode top cover assemblies, the negative electrode post is often made of a copper-aluminum composite plate structure or through friction welding, which results in high costs.

[0003] To reduce manufacturing costs, existing improved technologies propose using brazing to connect copper plates and aluminum pillars to form the negative electrode pillar. This solution allows for independent stamping of the copper plate and aluminum pillar, effectively controlling material costs. However, in practical applications, due to design flaws in the overall structure of the negative electrode top cover assembly, the brazed copper-aluminum interface is prone to stress, ultimately leading to connection failure and detachment at the brazed joint, severely impacting battery reliability. Utility Model Content

[0004] The purpose of this application is to provide a negative electrode top cover assembly and a secondary battery to solve the aforementioned technical problems.

[0005] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0006] This application provides a negative electrode top cover assembly, including: a first insulating component, a top cover sheet, a second insulating component, an aluminum component, a sealing component, a copper rivet, and a copper plate, wherein the top cover sheet is provided with electrode mounting holes;

[0007] One end of the copper rivet has a lug structure, and the other end of the copper rivet is riveted to a copper plate; the end face of the lug structure is brazed to an aluminum part; a sealing element is fitted on the copper rivet; one end of the sealing element abuts against the lug structure through a second insulating element, and the other end of the sealing element abuts against the copper plate.

[0008] The radial dimension of the lug structure is larger than the radial dimension of the pole mounting hole.

[0009] In some embodiments, a gap exists between the aluminum component and the second insulating component in the horizontal direction.

[0010] In some embodiments, the other end surface of the copper rivet is provided with a blind hole.

[0011] In some embodiments, the side of the copper rivet is further provided with a stepped structure, and an annular groove is formed between the stepped structure and the copper plate.

[0012] This application also provides a secondary battery, including the aforementioned negative electrode top cover assembly.

[0013] Compared with the prior art, the beneficial effects of the embodiments of this application are:

[0014] The negative electrode top cover assembly and secondary battery provided in this application embodiment have a sealing element disposed between the second insulating element and the copper plate, so that one end of the sealing element can abut against the support hanging ear structure through the second insulating element, avoiding abnormal stress on the copper-aluminum interface, thereby improving the structural stability of the negative electrode top cover assembly and improving the reliability of the battery. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of the secondary battery provided in an embodiment of this application is shown;

[0017] Figure 2 A schematic diagram of the negative electrode top cover assembly provided in an embodiment of this application is shown;

[0018] Figure 3 An exploded view of the negative electrode top cover assembly provided in an embodiment of this application is shown;

[0019] Figure 4 Another exploded view of the negative electrode top cover assembly provided in an embodiment of this application is shown;

[0020] Figure 5 A cross-sectional view of the negative electrode top cover assembly provided in an embodiment of this application is shown;

[0021] Figure 6 It shows Figure 5 Partial schematic diagram;

[0022] Figure 7 A cross-sectional view of a portion of the structure of the negative electrode top cover assembly provided in an embodiment of this application is shown;

[0023] Figure 8 Another cross-sectional view of a portion of the structure of the negative electrode top cover assembly provided in an embodiment of this application is shown.

[0024] Illustration:

[0025] 10. Positive electrode top cover assembly; 20. Housing; 30. Negative electrode top cover assembly;

[0026] 31. First insulating component; 32. Top cover plate; 321. Pole mounting hole; 33. Second insulating component; 34. Aluminum component; 35. Sealing component; 36. Copper rivet; 361. Lug structure; 362. Copper plate; 363. Annular groove; 37. Gap; 38. Blind hole. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0030] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0031] Please see Figures 1 to 8 As shown in the embodiment of this application, a secondary battery is provided, comprising: a positive electrode top cover assembly 10, a housing 20, and a negative electrode top cover assembly 30. For example, the housing 20 is sealed to both the positive electrode top cover assembly 10 and the negative electrode top cover assembly 30.

[0032] The negative electrode top cover assembly 30 includes: a first insulating component 31, a top cover plate 32, a second insulating component 33, an aluminum component 34, a sealing component 35, a copper rivet 36, and a copper plate 362. The top cover plate 32 is provided with an electrode mounting hole 321.

[0033] One end of the copper rivet 36 has a lug structure 361, and the other end of the copper rivet 36 is riveted to a copper plate 362; the end face of the lug structure 361 is brazed to an aluminum part 34; a sealing element 35 is sleeved on the copper rivet 36; one end of the sealing element 35 abuts against the lug structure 361 through a second insulating element 33, and the other end of the sealing element 35 abuts against the copper plate 362.

[0034] The radial dimension of the lug structure 361 is larger than the radial dimension of the pole mounting hole 321. For example, when it is circular, this radial dimension is the diameter. Or, for example, when it is square, this radial dimension is the corresponding side length.

[0035] As an example, please refer to Figure 8As shown, in the horizontal direction, there is a gap 37 between the aluminum part 34 and the second insulating part 33.

[0036] It should be noted that in some embodiments, the gap 37 may be provided; in other embodiments, the gap 37 may not be provided, so that the aluminum part 34 and the second insulating part 33 are in close contact.

[0037] As an example, please refer to Figure 8 As shown, the other end of the copper rivet 36 has a blind hole 38. It should be noted that, compared to the copper rivet 36 without the blind hole 38, the copper rivet 36 with the blind hole 38 has a tighter and more reliable riveting connection with the copper plate 362.

[0038] As an example, the side of the copper rivet 36 is also provided with a stepped structure, and an annular groove 363 is formed between the stepped structure and the copper plate 362, and the seal 35 is installed in the annular groove 363.

[0039] The negative electrode top cover assembly and secondary battery provided in this application embodiment form the negative electrode post by brazing, which can reduce material costs. Furthermore, the sealing element 35 is disposed between the second insulating element 33 and the copper plate 362, allowing one end of the sealing element 35 to abut against the supporting lug structure 361 through the second insulating element 33. This avoids abnormal stress on the copper-aluminum interface, thereby improving the structural stability of the negative electrode top cover assembly 30 and enhancing the reliability of the battery.

[0040] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A negative electrode top cover assembly, characterized in that, include: The components include a first insulating element, a top cover plate, a second insulating element, an aluminum component, a sealing component, a copper rivet, and a copper plate, wherein the top cover plate is provided with pole mounting holes; One end of the copper rivet has a lug structure, and the other end of the copper rivet is riveted to the copper plate; the end face of the lug structure is brazed to the aluminum part; the sealing element is sleeved on the copper rivet; one end of the sealing element abuts against the lug structure through the second insulating element, and the other end of the sealing element abuts against the copper plate. The radial dimension of the lug structure is greater than the radial dimension of the pole mounting hole.

2. The negative electrode top cover assembly according to claim 1, characterized in that, In the horizontal direction, there is a gap between the aluminum component and the second insulating component.

3. The negative electrode top cover assembly according to claim 1, characterized in that, The other end of the copper rivet has a blind hole.

4. The negative electrode top cover assembly according to claim 1, characterized in that, The side of the copper rivet is also provided with a stepped structure, and an annular groove is formed between the stepped structure and the copper plate.

5. A secondary battery, characterized in that, Includes the negative electrode top cover assembly as described in any one of claims 1 to 4.

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